Analyzing Plant Cell Wall Ultrastructure by Scanning Near-Field Optical Microscopy (SNOM).

The importance of lignocellulosic materials in various research areas including for example biorefinery processes and new biomaterials is constantly rising. Therefore, a detailed knowledge on the macromolecular assembly of plant cell walls is needed. However, despite the tremendous progress in the structural and chemical analysis of plant cell walls there are still uncertainties concerning the ultrastructure. This is either due to Rayleigh criterion based limitations of the analytical methods or the relatively low chemical information gained with high spatial resolution techniques. In this chapter scanning near field optical microscopy (SNOM) is presented as a powerful tool for the subdiffraction limited chemical and structural characterization of plant cell walls.